2) Activates and increases the number of osteoclasts, thus
increasing the rate of bone destruction and making calcium and phosphorus
available.

3) Delays formation of osteoblasts (bone forming cells).

4) Increases renal and intestinal absorption of calcium and
excretion of phosphate (PO4). Phosphate is important in maintaining our body's
acid-alkaline balance and helps in regulating carbohydrate digestion.

Parathormone and vitamin D are our body's principal regulators
of calcium and phosphorus balance. Without enough vitamin D the effects of
parathormone are decreased.

Parathormone secretion has its maximum effect on phosphate
in 2-3 hours, on calcium in 8 hours.

A decrease in serum calcium will stimulate parathormone activity
and cause hypertrophy of the parathyroid (common in rickets, pregnancy, lactation).

Too much serum calcium causes decreased activity and shrinking
of the parathyroid.

4) Pregnant mothers with high serum calcium (see #2 for probable
causes of increased serum calcium) will cause their fetus to have high serum
calcium levels. The parathyroid of the fetus will be inhibited. This will
usually, though not always, correct itself after birth.